The present invention relates to a large-diameter a.c. motor with a stator having joints. The stator carries a stator coil formed of windings which are arranged in two layers and disposed in grooves. The stator also has switching connections extending over its circumference, in which the stator coil is divided into several zones of closed windings. These zones correspond to the number of joints. The closed windings lie only in the groves between the joints.
Such divisible stators of large-circumference a.c. motors, especially of a synchronous design, are known. Due of the special structure of the stator coils described in DE-C-761 310, to simplify assembly of the a.c. motor at the installation site, the joints are not covered by windings. Only the switching connections are passed over the joint, and can be connected with each other at the joint such that they can be released, in known manner. In an a.c. motor with such a construction, each of the grooves of the stator adjacent to the joint is only occupied with one winding layer.
The armature reaction changes at the one-layer arrangement of the winding sides in the grooves adjacent to the joint. The present invention seeks to reduce the resulting disadvantages in the operation of such a machine.